Makefile install: Add --no-run-if-empty to xargs.

Makefile

@@ -3,13 +3,14 @@ PREFIX = ~/.micropython/lib
 all:
 
 # Installs all modules to a lib location, for development testing
-CMD="find . -maxdepth 1 -mindepth 1 \( -name '*.py' -not -name 'test_*' -not -name 'setup.py' \) -or \( -type d -not -name 'dist' -not -name '*.egg-info' -not -name '__pycache__' \)| xargs cp -r -t $(PREFIX)"
+CMD="find . -maxdepth 1 -mindepth 1 \( -name '*.py' -not -name 'test_*' -not -name 'setup.py' \) -or \( -type d -not -name 'dist' -not -name '*.egg-info' -not -name '__pycache__' \)| xargs --no-run-if-empty cp -r -t $(PREFIX)"
 install:
 	@mkdir -p $(PREFIX)
 	@if [ -n "$(MOD)" ]; then \
 	    (cd $(MOD); sh -c $(CMD)); \
 	else \
 	    for d in $$(find -maxdepth 1 -type d ! -name ".*"); do \
+	        echo $$d; \
 	        (cd $$d; sh -c $(CMD)); \
 	    done \
 	fi